NONLINEAR POLARIZATION AND SPECTROSCOPY OF VIBRONIC TRANSITIONS IN THE FIELD OF INTENSIVE ULTRASHORT PULSES

The interaction of intensive ultrashort light pulses with electronic transitions in a strongly broadened vibronic system with non-Markovian relaxation (e.g., a complex molecule or an impurity center in a crystal) is considered theoretically. The problem of calculating the non-linear polarization in such a system has been solved for the case of Gaussian-Markovian modulation of the electronic transition frequency. Similarities between the situation studied and electronic transfer reactions are discussed. Generalizationof our approach to the quantum character of a system of optically active low frequency vibrations modulating electronic transitions is also studied. A generalization of the theory to pump-probe femtosecond experiments for the case of sufficiently intensive pump pulses has been made. © 1990.